This cave under The Chihuahua Desert in Mexico is actually a working mine that is known for its amazing crystals. The name of the cave is Naica Mine, is located 1000ft under ground, and it was discovered by two miners that was also brothers when they were drilling into the Naica lead. The chamber of the crystals is known as Crystal Cave of Giants.
The biggest crystals weigh 55 tons and are measuring up to 36 feet long. Imagine what an incredible experience it would be to stand in the cave and experience the beauty of the crystals. One other attraction in Mexico is the Island of the Dolls, a rather dark and scary attraction.
They are blade-sharp and dangerous but awesome to look at. From the pictures you would suppose that it is icing cold in the cave, but to be honest it is about 112F, and the cavers need to bring cooled air in backpacks and be protected by special suits for the conditions.